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M. M. MERRITT.

cALvANoPLAsTlc PROCESS AND PRODUCT AJ APPLICATION FILED NOV. 2, 1911.

Patented Oct. 22, 1918.

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MATTHEW M. MERRITT, OF SOUTH MIDDLETON, MASSACHUSETTS, ASSIGNOR T COPPER PRODUCTS COMPANY, 0F BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

Specification of Letters Patent.

.- Application led November 2, 1917. Serial No. 199,810.

To all whom t may concern:

Be it known that I, MArrHEW M. Mnnnrr'r, a citizen of the United States, and a resident of South Middleton, county of Essex, Commonwealthf Massachusetts, have invented an Improvement in Galvanoplastic Processes and Products A,'of which the following description, in connection' with the accompanying drawings, is a specification, like characters on the drawings representing like parts. e

This invention pertains to improvements in galvanoplastic processes and products, but more particularly, thou h not exclusively, to the manufacture o articles such as manifolds for internal combustion engines such as aeroplane engines.

In the drawings, which show one form of an illustrative embodiment of my invention:-

Figure l shows a manifold;

Fig. 2- is a diagrammatic section therethrough on the line 2 2 of Fig. 1.

Great difficulty. has been experienced in constructing manifolds for aeroplane engines of the requisite light weight which are strong enough to withstand4 the constant and excessive vibrationsl occasioned by the operation of the engine. Such manifolds are very likely to develop cracks, particularly adjacent the bent portions thereof. It has heretofore been attempted to manufacture such manifolds by the electrolytic deposit of copper on cathodes of metal fusible at a low temperature, and on cathodes of wax painted with graphite or other electrically conductive material, the core being melted out after the electrolytic deposit. Manifolds made by the usual methods, above-described, haveproved unsatisfactory because of brittleness and coarseness of texture of the deposited metal, this brittleness being accentuated at points adjacent curved portions of the desiderable portion thereof, preferably at least one-half, is only intermittently immersed in the electrolyte., This. aspect of my invention is not claimed herein being comprised n the subject .matter 0f a copending application Serial No. 247,966, filed August 2,

1918, While intermittent immersion improves the texture of the deposited metal, electrolytic deposits made on metallic cathodes having low melting points are, as heretofore made, likely to be rough and brittle. I believe this to be due to the tendency of certain ingredients of the fusible metal,

Patented Oct. 22, i918. v

which is usually an alloy of lead, to be at-V tacked by the electrolyte, and in some instances to be disassociated into negative ions traveling from the cathode to the anode.

Where, on the other hand, the cathode is formed of non-conductive material removable by fusion, by a solvent, or otherwise, and the surface 0f which is coated with an electrically conductive paint, such as graphite, bronze powder and the like, the deposited copper, as heretofore practised, has been brittle and of slight tensile strength. As stated in my co-pending application, filed herewith, I believe this to be due to the comparatively coarse texture of the conductive coating which is necessarily full of interstices as compared with cast, rolled, er electrolytically deposited metal. 'Ihe unevenness of attraction exerted by this surfacing of the cathode results in combining the deposited metal in relativelyV coarse crystalline formation, which renders it brittle and of slight tensile strength.

I have found that the deleterious effects of a cathode composed of metal having a vlow fusing-point may be minimized by coating the metal with a film of a foreign substance such as Tease, and that if a layer of copper, prefera ly relatively thin, be electrolytically deposited subsequent to the application of the grease and the surface of this metal treated with mercury or mercury amalgam, that subsequent electrolytic deposits on the mercury amalgamated surface will be of ne texture and of great tensile strength, the brittleness being greatly reduced if n'ot eliminated.

If desired, the structure may be laminated by the occasional interruption of electrolytic deposit and the application to the surface of the deposited metal of either a film of grease or a film of mercury amalgam.

Where it is necessary or desirable to utilize -a non-metallic cathode such as wax or any electrically non-conductive material removable by alsolvent or otherwise, the same beingcoated with a paint of electrically conductive material, I have found it of great advantage to deposit a relatively thin sheet of copper or other metal on the electrically conductive surface, to treat this surface with mercury and to continue the electrolytic deposit on the' amalgamated surface, the secf ond deposit being very line-grained and of relatively high tensile strength compared with the initial deposit, and the initial deposit being improved in these respects by the combined effects of the mercury, the electrolyte and the current during subsequent electro-deposition.

In my co-pending application, iiled herewith, I have described the utilization of grease for purposes of securing improved electro-deposition, and, if desired, to secure a laminated structure. It is obvious that for some purposes a combination of the use of mercury and of grease may be desirable. I have elected to incorporate in the present application those claims ofsufliciently broad scope to dominate both inventions. I have used the word grease generically to define any substance capable of forming a film of electrically non-conductive material over the surface on which the metal. is to be deposited.

After electro-deposition the core Suitable method.

I have utilized the word galvanoplastic in its broader sense to include any electrolytic processes in which the entire cathode orany portion thereof is removed subsequent to electro-deposition. v

It is obvious that the cathode may,.if de-Y sired, 'be exterior tothe surface thereof on which metal is to be deposited, and that for some purposes my invention may be useful in connection with galvanoplastic processes in which the cathode can be withdrawn without change in the structure thereof.

' While I have shownand described one embodiment of my invention and one method of ractising the same,- it will be understood t at major changes may be made, bothv in the product and the method of proof the I cathode may be removed by fusion, by burning, by the use of a solvent or any'otherducing the same, without departing from the scope of my invention, which is best defined in the following claims.

Claims: 1. A hollow article having ashell formed of a pluralityl Aof electrolytically deposited metallic lamlnae, said laminas being separated by a substance having relatively slight ductive material, a layer of electrolytically deposited metal exterior to said granular material, said layer of metal having an eX- terior application of a foreign substance and a second coating of electrolytically deposited metal exterior to said foreign substance.

5. The galvanoplastic process which comprises coating a removable mold or core with an electrically conductive paint, and electrolytically depositing metal thereonvwhile rotating the mold or core under partial submergence in an electrolyte, the direction of rotation being periodically reversed.

manifold having a tubular portion 6 corgising a plurality of superimposed metal ic laminae.

7. A manifold having a tubular portion comprising a plurality of superimposed metallic laminae, with a foreign substance interposed between said laminae.

8. A hollow article formed of a plurality of layers of electrolytically deposited metal with a foreign substanceinterposed between said layers.

In testimony whereof, I havesigned my name to this specificatie MATTHEW M.` MERRITT. 

